The six currently recognized species in this genus are:[1][2] Scoloplax is distributed in South America in Peru, Bolivia, Brazil, and Paraguay.

[5] Species of Scoloplax are readily distinguishable from other catfishes by the presence of a conspicuous shield-shaped rostral plate bearing numerous large and recurved odontodes.

[3] Scoloplax species have modified stomachs that are enlarged, thin-walled, and clear.

A small patch of muscular tissue represents the digestive portion of the stomach, located from the entrance of the esophagus to where the intestine exits.

[6] Scoloplax species are fairly common among leaf litter in clear and blackwater habitats, including oxbow lakes, backwater pools, and well-vegetated streams.